In recent years, various types of memory cards, which are attachable and detachable relative to a host device and thereby handily portable, are widespread along with an increasingly developed larger capacity of a non-volatile semiconductor memory such as a flash memory.
An example of the memory cards is a memory card having a PC card size standardized as the PC Card Standards by the PCMCIA (Personal Computer Memory Card International Association).
In the PC Card Standards, a physical shape and a size of the card, examples of which are nominal dimensions of basic data such as a shape, a width, a length and a largest thickness of the card and tolerances of the dimensions, as well as a signal interface relative to the host device, are regulated. To exemplify the physical size of the card, a card whose nominal dimension of a width is 54.0 mm, nominal dimension of a length is 85.6 mm, and nominal dimension of a thickness in a thickest part is 5.0 mm is Type II. A card having the same nominal dimensions as in the Type II in width and length, whose nominal dimension of a thickness in a thickest part is 10.5 mm is Type III, and other similar sizes, are regulated.
Further, a memory card increasingly made available particularly for consumer use is a so-called compact-size memory card having a size smaller than that of the PC card and used as a recording medium in a commercial device such a digital camera and a mobile audio player.
As examples of the compact-size memory card, a generally called compact flash (Registered trade mark) card, smart media (Registered trade mark), memory stick (Registered trade mark), SD memory card (Registered trade mark) and the like are publicly known. “Interface”, issued in December 1999, p. 52-p. 55 (CQ Publishing CO., Ltd.) discloses examples of those cards. A specification of the SD memory card (Registered trade mark), such as a shape, a size, and the like thereof, is determined by the SD Association.